Performance analysis of switched-sector antennas for indoor wireless LANs

Given the potential market for wireless LAN (WLAN) technology, capacity within the available 2 and 5 GHz frequency bands is likely to fall short of market demands. Multiple-sector antenna arrays are known to be able to provide capacity enhancement by means of interference reduction through spatial filtering. In this paper, the performance of an eight-element circular array acting as an Access Point (AP) in indoor wireless LAN environments is analysed. Spatial-temporal channel data used within the analysis were obtained from physical measurements within numerous indoor environments using a state-of-the-art wideband vector signal analyser. Performance analysis of the array employing a switched-sector controller within the Hiperlan/2 standard is appraised in terms of carrier-to-interference (C/I) ratios. Results show that an isolation of up to 15dB can be achieved between the two polarisations, by means of using an antenna array at the AP. It is shown that 54% of the time, 2 users per timeslot can be supported by the system.